How does a float switch work in a tank

  A float switches are general liquid level switches,and are used to detect liquid level.Operation priciple of float switch is based on buoyancy,when the level of a liquid rises or falls,the float do the same action,float switch utilize a magnetic reed switch,when a magnet comes close to the switch,it close a circuit between the two lead wires and allowed current pass through it.

  In most stye of float switch,the reed switch is hermetically sealed in a stem,often it made from sus304 or pp.The float can move up and down as the level of liquid raises and falls,when the magnet which is encased in a float closed to reed switch,the circuit is  completed,then the switching signal is coming out.If use float switch properly,it can deliver millions of on/off cycles.